There is a lot to learn for new pool owners and much of what you need to know relates to pool chemistry. Pool chemistry is what keeps your pool clean and safe to swim in, but it does entail a bit of a learning curve. In addition to regular water checks and cleaning, you will also, on occasion, need to do something called shocking your pool. This sounds pretty scary, and it does entail the use of strong chemicals, but it is part and parcel with keeping your pool clear and clean.
There is a lot of debate as to how often it is necessary to shock your pool and the frustrating answer is, well, it depends. If you have a pool with an automatic cover, or it is an indoor pool, you may not have to shock your pool as often. It may need to be shocked more often with heavy use or changes in sunlight and weather patterns. While there isn’t much agreement as to how often a pool should be shocked, many pool owners do it about twice a month. Some do it once a week. It depends on your pool’s level of usage, the amount of sunlight it gets, and the weather.
What Does It Mean to Shock a Pool?
In essence, shocking simply refers to super chlorinating your pool to sanitize and kill any potentially-harmful bacteria, viruses, and pesky things like algae and mold. Not only does it help to reduce the amount of buildup and dangerous nasties in your pool, but it also removes what are called chloramines. Chloramines are combined with chlorine molecules. What happens is that the chlorine binds with sweat, oils, and other organic substances. Shocking will also eliminate these rather gross chloramines as well.
Why Do You Need to Shock Your Pool?
Many people don’t understand the need to shock a pool given that they regularly put chlorine and acid in their pool systems. While this does a lot, some organisms can survive in treated pool water. Some seem to be unaffected by these chemicals. Things like algae can build up over time and chloramines are just part of pool ownership. While the regular chemicals you use do keep the water sanitized, it does need a little extra “help” on occasion. This is where shocking comes in.
In addition to regular shocking to keep up with any organisms that may be making their home in your pool, there are a few other instances where you will need to shock your pool.
- During times of intense sunshine: Solar light breaks down chlorine, which will render it ineffective at keeping your water safe. Periods, where there is a lot of intense, prolonged sunlight, will require you to shock your pool more often. When the sun is intense, it can cause your pool to lose up to 5/ppm of chlorine a day, which is not something that most automatic systems are designed to keep up with. Left unattended, it would cause the chemical levels in your pool to crash completely.
- Lots of pool traffic: If your pool gets a lot of use, you will need to shock your pool more. Swimmers, try as they might bring contaminants and potentially-harmful substances into pools. Sunscreen, sweat, makeup, skin oil, residue from shampoo, conditioner or soap – all of these things can do a number on the ability of chlorine to keep up with the water’s sanitation needs.
- Excessive rainwater: Periods of intense rain can also necessitate the need to shock your pool. If you do not keep your pool covered when not in use, heavy rain will likely dilute your pool water. This will lead to reduced chlorine levels and thus reduced sanitation.
More On When to Shock Your Pool
If one of the things mentioned above happens, it is time to shock your pool. The same is true if someone urinates or worse in the pool. The problem is that a lot of people wait until things get worse before they think to shock their pool. This means when there is excessive algae or mold growth, or when the clarity of the water is significantly reduced. Having a schedule with which you shock your pool can help you avoid these things ever getting out of control in the first place.
If, when doing your regular water test, you notice the free chlorine drops below 3/ppm, you will need to shock the pool. Chlorine that is “free” is chlorine that can sanitize the water. “Non-free” chlorine is ineffective. High levels of combined chlorine also indicate a need to shock. Finally, when you close your pool down for the season or get ready to be opened for the season, you will need to shock the water.
How to Shock a Pool
First, you want to make sure that you are taking appropriate safety measures. Pool shock is a strong chemical that can be harmful if it gets in your eyes or on your skin, and it can also damage clothing. Wearing protective gloves and glasses, as well as clothes you don’t mind ruining, is imperative. Next, you will want to measure out the pool shock according to the manufacturer’s instructions. You must follow these steps as they are written and do not deviate. Preparation will be different depending on whether you are using liquid, granular, or powdered shock.
Next, you add chemicals to the pool water according to the instructions for the type of pool shock you are using. It may need to be added to the return jets where it can be easily circulated, or you may need to pour it manually around the pool. Once it is shocked, you simply have to leave it alone and wait for the shock to do its job. It can be dangerous to get into a pool too soon after shocking it. It is recommended to leave the pool overnight and then test the water before assuming it has returned to safe levels of chlorine.
Foamy Pool Water After Shocking
Using shock treatment in your pool should not cause the water to become foamy – If it does, there’s something else that needs to be adjusted to correct this. If you find that your pool water is foamy after you shock it, check out our article here on how to deal with a foamy pool.
What To Look For When Choosing Pool Shock
When purchasing shock, look for smaller bags, since they will last longer than large packages (which will be harder to keep airtight). All good quality shock should be fairly fast acting when used as directed. Be sure to carefully read the instructions, as each brand may have slightly different directions.
Below are the top 3 bestselling pool shock treatments available on Amazon. You can’t go wrong with any of these options – they’re all awesome and have excellent reviews.
- The In The Swim Pool Winterizing and Closing Chemical Kit is designed to save you time and money by including all the necessary chemicals to close your pool. Making for a simpler pool closing experience, and providing an easy transition for pool opening season come spring.
- Unlike chlorine-based winter kits that reduce the effectiveness of other pool winterizing chemicals and can stain, bleach or damage pool surfaces, our chemical kits won't damage your pool during winter.
- Designed for pools of all shapes and sizes. If your pool is between sizes we suggest you buy the next size up. You can buy multiple kits for pools larger than 35,000 gallons.
- Made exclusively for In The Swim, the Winter Sorb can absorb up to 40 times its weight in residual suntan lotions and body oils to prevent grease, grime and waterline scum.
- Kit Includes:1 Qt. Winterizer, 1 Qt. Winter Stain-Away, 2 Lb. Chlorine Free Pool Shock, 1 Winter Sorb, and 1 Winter Pool Floater
- Prevents and treats pool algae
- Built in clarifier
- Non-foaming formula
- Suitable for all pool types
- Packaging may vary*
- Floats under your winter cover all season
- Performs well with mesh safety covers
- Patented 6-month delivery system
- Safe for all surfaces and filters
- One small WinterPill treats up to 30,000 gal
If you click this link and make a purchase, we earn a commission at no additional cost to you. Last update on 2023-09-08